Apple - How to share Mac audio over Skype with the microphone?

Turns out I had some strange Core Audio driver issue. Every time Skype was running, process "coreaudiod" would fire up and begin to hog CPU like crazy. I fixed permissions on my boot volume and it fixed a bunch of stuff related to iTunes, which apparently also fixed whatever was going on.

Once the coreaudiod issue was resolved, here's the setup that is working perfectly:

  1. Skype "microphone" (input) set to Soundflower (2ch)
  2. Aggregate Device created, consisting of Built-In Microphone and Soundflower (2 ch.)
  3. Reason set to use the Aggregate Device
  4. SoundflowerBed set to output to Balance.

Now all I have to do is create an audio track and enable monitoring, and I can hear myself in the mic, while normal Reason audio flows out both to Skype and my Balance to my headphones, and all is well with the world.